1. Field of the Invention
The present invention relates to a power feeding system that performs non-contact power feeding which is represented by, for example, non-contact charging. In addition, the present invention relates to a positioning control method that is implemented in the power feeding system and is concerned with a charging position for a power feeder and power-receiving equipment.
2. Description of the Related Art
A technology for charging electronic equipment (secondary battery) in a non-contact manner has been known in the past.
For the non-contact charging, for example, a primary coil is incorporated in a charger and a secondary coil is incorporated in electronic equipment. For charging, the electronic equipment is placed at a given specified position in the charger and the primary coil is driven. Accordingly, induced electromotive force is exerted between the primary coil and secondary coil. In the electronic equipment, the induced electromotive force is used to charge a secondary battery.
In a system in which non-contact charging is performed as mentioned above, when electronic equipment is placed on a charger, the electronic equipment has to be positioned so that a state in which the distance between an internal primary coil and secondary coil falls below a certain value will be retained. In a state in which the distance between the primary coil and secondary coil is equal to or larger than the certain value, the coupling between the primary coil and secondary coil becomes insufficient. Eventually, appropriate transmission of power fails.
For the positioning, a constitution in which after a magnetic pole member of a stand is opposed to a magnetic pole member of electronic equipment, when the main body of the electronic equipment is abutted on the external surface of the stand, the electronic equipment is reliably mounted owing to attraction is described in JP-A-4-197040 (patent document 1).
As described in JP-A-63-59734 (patent document 2), a method of engaging electronic equipment with a charger by forming a physical shape such as a concave part in one of them is widely known.
JP-A-6-153411 (patent document 3) discloses a constitution in which: a rechargeable battery is disposed together with a load in a moving unit in such a manner that the battery can be moved; and when the moving unit is located at a home position, a charging power supply performs non-contact charging on the rechargeable battery.
JP-A-2008-301553 (patent document 4) discloses a constitution in which: a mirror-finished surface bearing a permissible range mark indicating the center of a primary transmission coil is formed at a position equivalent to the position of the primary transmission coil incorporated in a mount of a cradle; and a center position mark is inscribed at a position equivalent to the position of the center of a secondary transmission coil incorporated in a portable cellular phone that is equipment to be charged. In the constitution, while the center position mark of the portable cellular phone is reflected on the permissible range mark of the mount, the center position of the secondary transmission coil is matched with the center position of the primary transmission coil and the portable cellular phone is placed on the mount. Thus, the portable cellular phone is readily located at the accurate position on the mount.